CoMOSat: Controller Placement in SDN-Enabled Multi-Orbit Satellite Networks

Satellite networks provide connectivity to remote areas, but efficient network management is crucial for seamless operations and resource optimization. Software-defined networks (SDN) offer flexibility, making them appealing for satellite network management. The dynamic placement of SDN controllers is crucial for an SDN-enabled satellite network, as it must adapt to dynamic topology changes, potential disruptions, limited capacity, and considerable latency. Existing literature lacks dynamism for controller placement in satellite networks considering multi-orbit scenarios, time-varying load and topology and facilitating swift adaptation to network variations. This work optimizes network performance by strategically positioning SDN controllers in multi-orbit satellite networks using a genetic algorithm based on network topology, traffic distribution, and link stability constraints considering low-earth and medium-earth satellites. The proposed scheme is evaluated through simulations using operational constellation parameters, showing 33.13% and 6.17% reduction in controller count than benchmarks static placement with dynamic assignment (SPDA) and fixed placement (FP).